Anytime I overexert it doesn't hit me until I'm sleeping. Then, I will be woken up and I'm absolutely red lining. Nerve pain all over, heart beating hard, trouble breathing because my lungs feel tight, tinnitus louder, increased cognitive difficulties. I'll just be totally buzzing. I'm still extremely tired during this time but there's another part of me that is so revved up its impossible to sleep. This will last usually a few hours before calming down but then it leaves me with some new deficit- usually cognitive. Dissociation will be worse, psychosis, dementia, anxiety... something. And of course I'll have no sleep that night. However it doesn't matter how tired or fatigued I am, this heightened state will keep me awake for hours or days sometimes. I've never heard of anyone having PEM like this.